Ultrasonic diagnostic technique utilizing switched gain signal processing

摘要

An ultrasonic diagnostic technique utilized to determine the wall thickness of cardiac structures. In a preferred embodiment, the endocardial and epicardial surfaces of the left ventricular posterior wall are irradiated with an ultrasonic sound beam. The signal reflected at the epicardial-lung interface is much stronger than the signal from the surrounding myocardium and endocardial surface. In order to simultaneously visualize the endocardial and epicardial reflected signals, the echos received therefrom are processed through a switched gain receiver. That is, an oscillator rapidly switches the receiver gain between two levels that are independently set to display the two wall surfaces, the resultant echocardiogram displaying the high and low gain portions closely mixed whereby the wall thickness may be readily determined.